Heat vegetable oil in large skillet over medium heat.,Saute onions and jalapenos about 3 minutes.,Add garlic, and saute 30 seconds, or until golden.,Add beef strips to skillet.,Stir in corn, beans, tomatoes, cilantro, cumin, chili powder, salt and pepper, and cook 10 minutes.,Meanwhile, bring 3 cups vegetable stock to a boil in large saucepan.,In small bowl, combine 1 cup vegetable stock with cornmeal.,Blend into boiling stock, stirring constantly to avoid lumps, and stir until smooth.,______,Remove from heat.,Preheat oven to 350F.,Spoon cornmeal mixture into 12x8-inch baking dish, and bake 20 minutes.,Remove from oven, layer beef mixture on cornmeal and sprinkle cheese on top.,Bake 10 minutes more, or until cheese melts.,Remove from oven, and serve.